Cylinder head Service:
WE specialize in RotoCast cylinder heads Found on Audi and Lamborghini models :
Porting is basically opening up, re-configuring and re-surfacing the ports of a cylinder head. Why port a cylinder head? The simple answer is to let the engine breath easier and more efficiently and therefore produce more power.
Cylinder head ports fall into two basic designs; the Straight Shot port and the High Approach port. In a Straight Shot port, the design allows for a line of sight from the inlet directly to the front opening of the intake valve. Sometimes this design gives a lower flow value but obtains a higher velocity of fuel/air entering the combustion chamber. It also creates a turbulent spin or swirling in the combustion chamber, yielding a more efficient and more complete burn.
A High Approach port is where a turn is necessary in the port design. The term "high approach" comes from the angle of the last section of the port relative to the valve - it is more in-line with the valve stem.
We take advantage of this to get a full volume flow path in the complete 360° circumference of the valve. Making a turn to airflow is problematic but we caress the turn - making it as moderate and efficient as possible - to use it in our favor. The straight shot into the opening yields a fuller, more uniform flow around the entire valve curtain. The advantage is that the total valve opening is used more completely.
Which approach we take is based on the original design of the head. For example, the Audi 5v head uses a Straight Shot port while the 16v Porsche head tends toward a High Approach port
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Our Cylinder Head Porting Methodology:
We take a very serious and methodical approach to cylinder head porting. We do not offer porting on heads that we have not developed an in house program for first, Typically 6 months to a year . The first step is to use the traditional method of hand porting using grinding tools and our past experience and knowledge for shape and sizing. The port is then run through preliminary tests on a flow bench.
Once a design looks good, we copy it
to all four cylinders (x2 pair) and then go to the dynamometer for the real test. While the flow bench gives a good indication of how a port will work, the truth is at the dyno as it more accurately simulates real-world conditions and loads the engine.
We sometimes make as many as 30 pulls on an engine dynometer to work in a design. This is the Reason we do not offer porting on heads that we have not developed in house first.
The heads get disassembled and ports re-ground to wring out every bit of power we can get. It is a painstaking approach but we feel it is the absolute best way to do it.
The final design is then digitized utilizing a Renishaw Probe on a 5-axis Haas CNC machine. This allows us to trace our absolute best design and reproduce it exactly for each cylinder. One of the benefits of CNC porting is that each cylinder is an exact duplicate. If one cylinder is down on power we know it is not the porting and that takes a variable out of the equation.
Customers cars get our pre formulated heads, in some cases the engine is removed and reinstalled, then a few pulls on a chassis dyno again to show achievement
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Complete Cylinder Head enhancement:
Cylinder heads can be built up with different machining and component additions. The key is the combination of elements. For example, porting combined with larger valves can greatly increase horsepower, but the engine really comes to life when custom cams are put into the mix..
1) Full Radius Valve Job :
The most critical, high velocity flow around a valve is right at the valve seat. The full radius valve job focuses on this area. Performed on a Serdi 60 machine utilizing our custom-designed tooling, ensures that valve edges are smooth for the best flow. The valve height is kept at a standard so we don't loose compression ratio. Many times we can achieve a better seal than at the factory. A full radius valve job alone can yield approximately a 3% gain in horsepower..
2) Porting:
Porting is by far the biggest single gain for a normally aspirated motor. All port jobs come with a full radius Valve job. Up to 30 to 50 horsepower gains can be expected on some applications.
3) Valves and Valve Seats:
To get more flow into a cylinder you can simply make the hole larger. This is accomplished by the installation of larger valves. We offer valves in a virtually limitless variety of sizes and materials. There are two types of stainless steel valves available (regular and cryogenic) as well as titanium or sodium filled titanium valves. In addition to standard oversizes we can have custom valves made.
For more information regarding MotoDyne's Cylinder head Services please contact our
Technical Staff.
